U.S. patent application number 15/401625 was filed with the patent office on 2017-10-19 for method of manufacturing multilayer ceramic electronic component and multilayer ceramic electronic component.
The applicant listed for this patent is SAMSUNG ELECTRO-MECHANICS CO., LTD.. Invention is credited to Hye Young CHOI, Ki Pyo HONG, Bong Jun JUHNG, Doo Young KIM, You Na KIM.
Application Number | 20170301469 15/401625 |
Document ID | / |
Family ID | 60040172 |
Filed Date | 2017-10-19 |
United States Patent
Application |
20170301469 |
Kind Code |
A1 |
JUHNG; Bong Jun ; et
al. |
October 19, 2017 |
METHOD OF MANUFACTURING MULTILAYER CERAMIC ELECTRONIC COMPONENT AND
MULTILAYER CERAMIC ELECTRONIC COMPONENT
Abstract
A method of manufacturing a multilayer ceramic electronic
component includes forming external electrodes on end surfaces of a
ceramic body, and more particularly, to forming external electrodes
by attaching a sheet for forming an external electrode on a ceramic
body. A multilayer ceramic electronic component thus formed has
external electrodes with a thin and uniform thickness.
Inventors: |
JUHNG; Bong Jun; (Suwon-si,
KR) ; KIM; Doo Young; (Suwon-si, KR) ; HONG;
Ki Pyo; (Suwon-si, KR) ; KIM; You Na;
(Suwon-si, KR) ; CHOI; Hye Young; (Suwon-si,
KR) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
SAMSUNG ELECTRO-MECHANICS CO., LTD. |
Suwon-si |
|
KR |
|
|
Family ID: |
60040172 |
Appl. No.: |
15/401625 |
Filed: |
January 9, 2017 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
H01G 13/006 20130101;
H01G 4/30 20130101; H01G 4/012 20130101; H01G 4/248 20130101; H01G
4/232 20130101; H01G 4/12 20130101 |
International
Class: |
H01G 4/30 20060101
H01G004/30; H01G 4/012 20060101 H01G004/012; H01G 4/12 20060101
H01G004/12; H01G 4/248 20060101 H01G004/248 |
Foreign Application Data
Date |
Code |
Application Number |
Apr 19, 2016 |
KR |
10-2016-0047754 |
Claims
1. A method of manufacturing a multilayer ceramic electronic
component, comprising: preparing an elastic punching material and a
member having a sheet for forming an external electrode above the
elastic punching material; stacking ceramic sheets, on which
internal electrode patterns are formed, to form a ceramic body
including internal electrodes disposed to face each other with
respective dielectric layers interposed therebetween; pressing and
closely adhering the ceramic body to the sheet for forming an
external electrode, to attach the sheet for forming an external
electrode to the ceramic body; and forming an external electrode on
an end surface of the ceramic body in a length direction, by
cutting the sheet for forming an external electrode using the
elastic punching material.
2. The method of claim 1, further comprising: attaching a release
film to the elastic punching material; and attaching the sheet for
forming an external electrode to the release film.
3. The method of claim 2, wherein the release film is a
polyethylene terephthalate (PET) film.
4. The method of claim 1, wherein the external electrode is formed
up to corner portions of the ceramic body.
5. The method of claim 1, further comprising, after forming the
external electrode on the end surface of the ceramic body,
preparing a member having an elastic pressing material above a
surface plate; and heating the surface plate to thereby extend the
external electrode to band portions of the ceramic body.
6. The method of claim 5, wherein the elastic pressing material is
a pressing rubber.
7. The method of claim 1, wherein 0.8.ltoreq.T2/T1.ltoreq.1.2 in
which T1 is a thickness of the external electrode in a central
region of the ceramic body in a thickness direction and T2 is a
thickness of the external electrode at a point at which an
uppermost internal electrode in the thickness direction is
positioned.
8. The method of claim 5, wherein 0.4.ltoreq.T3/T1.ltoreq.1.0 in
which T3 is a thickness of the external electrode in a corner
portion of the ceramic body and T1 is a thickness of the external
electrode in a central region of the ceramic body in a thickness
direction.
9. The method of claim 1, further comprising: forming one or more
plating layers on the external electrode.
10. The method of claim 1, wherein the elastic punching material is
a punching rubber.
11. The method of claim 1, further comprising: pressing and closely
adhering the ceramic body to a sheet for forming an external
electrode, to attach the sheet for forming an external electrode to
the other end surface of the ceramic body; and forming a second
external electrode on the other end surface of the ceramic body in
a length direction, by cutting the sheet for forming an external
electrode on the other end surface of the ceramic body using an
elastic punching material.
12. The method of claim 11, further comprising: preparing a second
elastic punching material and a second member having a sheet for
forming an external electrode above the second elastic punching
material, wherein the sheet for forming an external electrode
attached to the second member is used as the sheet for forming an
external electrode on the other end surface of the ceramic body,
and the second elastic punching material is the elastic punching
material used for forming the second external electrode on the
other end surface of the ceramic body.
13. The method of claim 11, wherein: the sheet for forming an
external electrode on the end surface of the ceramic body is used
as the sheet for forming an external electrode on the other end
surface of the ceramic body, and the elastic punching material used
for forming the external electrode on the end surface of the
ceramic body is the elastic punching material used for forming the
second external electrode on the other end surface of the ceramic
body.
14. A method of manufacturing a multilayer ceramic electronic
component, comprising: attaching an elastic pressing material to a
first surface plate; preparing a member having a sheet for forming
an external electrode above the elastic pressing material; stacking
ceramic sheets, on which internal electrode patterns are formed, to
form a ceramic body including internal electrodes disposed to face
each other with respective dielectric layers interposed
therebetween; pressing and closely adhering the ceramic body to the
sheet for forming an external electrode, to attach the sheet for
forming an external electrode to the ceramic body; heating the
surface plate to extend the sheet for forming an external electrode
to band portions of the ceramic body; preparing a member having an
elastic punching material above a second surface plate; and
pressing and closely adhering the ceramic body having the sheet for
forming an external electrode on the elastic punching material to
cut the sheet for forming an external electrode, thereby forming an
external electrode on an outer surface of the ceramic body.
15. The method of claim 14, wherein a same surface plate is used as
both the first surface plate and the second surface plate.
16. The method of claim 14, wherein 0.8.ltoreq.T2/T1.ltoreq.1.2 in
which T1 is a thickness of the external electrode in a central
region of the ceramic body in a thickness direction and T2 is a
thickness of the external electrode at a point at which an
uppermost internal electrode in the thickness direction is
positioned.
17. The method of claim 14, wherein 0.4.ltoreq.T3/T1.ltoreq.1.0 in
which T3 is a thickness of the external electrode in a corner
portion of the ceramic body and T1 is a thickness of the external
electrode in a central region of the ceramic body in a thickness
direction.
18. The method of claim 14, further comprising: forming one or more
plating layers on the external electrode.
19. The method of claim 14, wherein the elastic pressing material
is a pressing rubber.
20. The method of claim 14, wherein the elastic punching material
is a punching rubber.
21. A multilayer ceramic electronic component comprising: a ceramic
body including dielectric layers and internal electrodes stacked
and alternately exposed to respective end surfaces of the ceramic
body with dielectric layers interposed therebetween; external
electrodes respectively disposed on end surfaces of the ceramic
body in a length direction; and one or more plating layers disposed
on each of the external electrodes, wherein
0.8.ltoreq.T2/T1.ltoreq.1.2 in which T1 is a thickness of the
external electrodes in a central region of the ceramic body in the
thickness direction of the ceramic body and T2 is a thickness of
the external electrodes at a point at which an uppermost of the
internal electrodes in the thickness direction is positioned.
22. The multilayer ceramic electronic component of claim 21,
wherein the external electrodes are only disposed on end surfaces
of the ceramic body in the length direction and are note disposed
on other surfaces of the ceramic body.
23. The multilayer ceramic electronic component of claim 21,
wherein the external electrodes are disposed up to corresponding
corner portions of the ceramic body.
24. The multilayer ceramic electronic component of claim 23,
wherein 0.4.ltoreq.T3/T1.ltoreq.1.0 in which T3 is a thickness of
the external electrodes in a corner portion of the ceramic body and
T1 is a thickness of the external electrodes in a central region of
the ceramic body in a thickness direction.
25. The multilayer ceramic electronic component of claim 23,
wherein the plating layers are disposed up to corresponding corner
portions of the ceramic body.
26. A multilayer ceramic electronic component comprising: a ceramic
body including internal electrodes alternately stacked with
dielectric layers; and external electrodes respectively disposed on
end surfaces of the ceramic body in a length direction and extended
on one or more adjacent surfaces; wherein
0.8.ltoreq.T2/T1.ltoreq.1.2 in which T1 is a thickness of the
external electrodes in a central region of the ceramic body in the
thickness direction of the ceramic body and T2 is a thickness of
the external electrodes at a point at which an uppermost of the
internal electrodes in the thickness direction is positioned.
27. A method of manufacturing a multilayer ceramic electronic
component, comprising: preparing a sheet for forming an external
electrode above an elastic punching material; pressing and closely
adhering a ceramic body, which includes a plurality of internal
electrodes interposed with dielectric layers, to the sheet for
forming an external electrode, to attach the sheet to the ceramic
body; and cutting the sheet for forming an external electrode using
the elastic punching material.
28. The method of claim 27, wherein: the elastic punching material
is formed above a surface plate, and the method further comprises
heating the surface plate to extend the sheet for forming an
external electrode to band portions of the ceramic body.
Description
CROSS-REFERENCE TO RELATED APPLICATION(S)
[0001] This application claims benefit of priority to Korean Patent
Application No. 10-2016-0047754 filed on Apr. 19, 2016 in the
Korean Intellectual Property Office, the disclosure of which is
incorporated herein by reference in its entirety.
BACKGROUND
1. Field
[0002] The present disclosure relates to a method of manufacturing
a multilayer ceramic electronic component and to a multilayer
ceramic electronic component.
2. Description Of Related Art
[0003] In accordance with a recent trend for the miniaturization of
electronic products, multilayer ceramic electronic components have
been required to have a small size and high capacitance.
[0004] Various methods have been attempted to decrease the
thickness of dielectric layers and internal electrodes and increase
the number of dielectric layers and internal electrodes in
multilayer ceramic electronic components. Multilayer ceramic
electronic components in which the thickness of dielectric layers
are decreased and the number of stacked dielectric layers are
increased have been recently manufactured.
[0005] As external electrodes have been required to have a
decreased thickness, a problem in which a plating solution
permeates into a chip through the thin portions of the external
electrodes may occur, such that it is technically difficult to
miniaturize the multilayer ceramic electronic component.
[0006] Where the external electrodes have non-uniform shapes, there
is an increased risk that the plating solution will permeate
through thin portions of the external electrodes, such that a
problem may occur in terms of securing reliability.
[0007] External electrodes formed using an existing dipping method,
or the like, may be formed on head surfaces corresponding to end
surfaces of a ceramic body in a length direction and on four
surfaces (hereinafter, referred to as "band surfaces") contacting
the head surfaces. In such a case, it may be difficult to uniformly
apply a paste for forming the external electrode due to dispersion
in the body and fluidity and viscosity of the paste, such that
there may be differences in the thickness of the applied paste.
[0008] The plating solution may permeate through a portion of an
external electrode where the paste is thinly applied due to a
decrease in density of the portion, such that reliability is
reduced. In addition, glass beading or blisters, where glass is
exposed to a surface, may be generated where the paste is thickly
applied, should the thickness of the plating layer be increased to
solve a plating defect and a shape defect.
[0009] When the thickness of the applied paste is thin and uniform,
a formation area of the internal electrodes may be increased, such
that capacitance may be significantly increased as compared to an
existing capacitor having the same size.
SUMMARY
[0010] An aspect of the present disclosure may provide a high
capacitance multilayer ceramic electronic component where an
external electrode has a thin and uniform thickness, and a method
of manufacturing the same.
[0011] According to an aspect of the present disclosure, a method
of manufacturing a multilayer ceramic electronic component may
include: preparing an elastic punching material and a member having
a sheet for forming an external electrode above the elastic
punching material; stacking ceramic sheets, on which internal
electrode patterns are formed, to form a ceramic body including
internal electrodes disposed to face each other with respective
dielectric layers interposed therebetween; pressing and closely
adhering the ceramic body to the sheet for forming an external
electrode, to attach the sheet for forming an external electrode to
the ceramic body; and forming an external electrode by cutting the
sheet for forming an external electrode using the elastic punching
material.
[0012] According to another aspect of the present disclosure, a
method of manufacturing a multilayer ceramic electronic component
may include: attaching an elastic pressing material to a first
surface plate; preparing a member having a sheet for forming an
external electrode above the elastic pressing material; stacking
ceramic sheets on which internal electrode patterns are formed, to
form a ceramic body including internal electrodes disposed to face
each other with respective dielectric layers interposed
therebetween; pressing and closely adhering the ceramic body to the
sheet for forming an external electrode, to attach the sheet for
forming an external electrode to the ceramic body; heating the
surface plate to extend the sheet for forming an external electrode
to band portions of the ceramic body; preparing a member having an
elastic punching material above a second surface plate; and
pressing and closely adhering the ceramic body having the sheet for
forming an external electrode on the elastic punching material to
cut the sheet for forming an external electrode, thereby forming an
external electrode on an outer surfaces of the ceramic body.
[0013] According to another aspect of the present disclosure, a
multilayer ceramic electronic component may include: a ceramic body
including dielectric layers and internal electrodes stacked and
alternately exposed to respective end surfaces of the ceramic body
with dielectric layers interposed therebetween; external electrodes
respectively disposed on end surfaces of the ceramic body in a
length direction and up to corner portions of the ceramic body; and
one or more plating layers disposed on each of the external
electrodes wherein, 0.8.ltoreq.T2/T1.ltoreq.1.2 in which T1 is a
thickness of each of the external electrodes in a central region of
the ceramic body in the thickness direction and T2 is a thickness
of each of the external electrodes at a point at which an uppermost
internal electrode in the thickness direction is positioned.
BRIEF DESCRIPTION OF DRAWINGS
[0014] The above and other aspects, features, and advantages of the
present disclosure will be more clearly understood from the
following detailed description taken in conjunction with the
accompanying drawings, in which:
[0015] FIGS. 1A through 1C are views illustrating a process of
forming an external electrode of a multilayer ceramic electronic
component according to an exemplary embodiment in the present
disclosure;
[0016] FIGS. 2A through 2C are views illustrating a process of
forming an external electrode of a multilayer ceramic electronic
component according to another exemplary embodiment in the present
disclosure;
[0017] FIGS. 3A through 3F are views illustrating a process of
forming an external electrode of a multilayer ceramic electronic
component according to another exemplary embodiment in the present
disclosure;
[0018] FIG. 4 is a perspective view of a multilayer ceramic
electronic component according to another exemplary embodiment in
the present disclosure;
[0019] FIG. 5 is a cross-sectional view taken along line I-I' of
FIG. 4; and
[0020] FIG. 6 is an enlarged view of region A of FIG. 5.
DETAILED DESCRIPTION
[0021] Hereinafter, exemplary embodiments of the present disclosure
will be described in detail with reference to the accompanying
drawings.
[0022] Directions of a hexahedron will be defined in order to
clearly describe exemplary embodiments in the present disclosure.
L, W, and T illustrated in the drawings refer to a length
direction, a width direction, and a thickness direction,
respectively. Here, the thickness direction may be the same as a
stacking direction in which dielectric layers are stacked.
[0023] Method of Manufacturing Multilayer Ceramic Electronic
Component
[0024] FIGS. 1A through 1C are views illustrating a process of
forming an external electrode of a multilayer ceramic electronic
component according to an exemplary embodiment in the present
disclosure.
[0025] Referring to FIGS. 1A through 1C, a method of manufacturing
a multilayer ceramic electronic component according to an exemplary
embodiment in the present disclosure may include attaching an
elastic punching material 160 to a surface plate 150 and preparing
a member having a sheet 130 for forming an external electrode above
the elastic punching material 160. Ceramic sheets on which internal
electrode patterns are formed can be stacked to form a ceramic body
110 that includes internal electrodes disposed to face each other
with respective dielectric layers interposed therebetween. The
ceramic body 110 can be pressed and closely adhered to the sheet
130 for forming an external electrode to attach the sheet 130 on
the ceramic body 110.
[0026] In order to form external electrodes on outer surfaces of
the ceramic body 110, the elastic punching material 160 may be
attached to the surface plate 150, and the member having the sheet
130 for forming an external electrode may be prepared above the
elastic punching material 160.
[0027] The method of manufacturing a multilayer ceramic electronic
component according to the exemplary embodiment may further include
attaching a release film 170 onto the elastic punching material 160
and attaching the sheet 130 for forming an external electrode on
the release film 170.
[0028] The surface plate 150 may serve as to support a member used
to form the external electrodes on the outer surfaces of the
ceramic body 110, and may be any material with low thermal
deformation, such as a stone surface plate using stone as a raw
material.
[0029] The elastic punching material 160 may serve to cut the sheet
130 for forming an external electrode attached to the outer
surfaces of the ceramic body 110. Therefore, the external
electrodes may be formed on both end surfaces of the ceramic body
110 in a length direction of the ceramic body 110,
respectively.
[0030] The elastic punching material 160 may be any material having
elasticity, such as a punching rubber.
[0031] The release film 170 may also serve to cut the sheet 130 for
forming an external electrode attached to the outer surfaces of the
ceramic body 110, and may be a polyethylene terephthalate (PET)
film. However, a material of the release film 170 is not limited
thereto.
[0032] The sheet 130 for forming an external electrode may be a
paste for forming an external electrode that is thinly applied and
then dried, and may be a green sheet.
[0033] In detail, the paste for forming an external electrode may
be prepared by mixing a conductive metal selected from the group
consisting of copper (Cu), nickel (Ni), palladium (Pd), platinum
(Pt), gold (Au), silver (Ag), or lead (Pb), or alloys thereof, a
binder, a plasticizer, and a dispersant, and the like, with each
other.
[0034] The paste for forming an external electrode may be applied
depending on a required thickness of the external electrode using a
doctor blade casting device, or the like, and then dried to prepare
the sheet 130 for forming an external electrode.
[0035] A method of forming the external electrodes on the outer
surfaces of the ceramic body can be performed by dipping the
ceramic body in the paste for forming an external electrode.
[0036] However, in a case of forming external electrodes using a
dipping method, or the like, the external electrodes are formed on
head surfaces corresponding to end surfaces of a ceramic body in
the length direction and band surfaces corresponding to four
surfaces contacting the head surfaces, and it is difficult to
uniformly apply the paste for forming an external electrode due to
generation of dispersion in the ceramic body and fluidity and
viscosity of the paste, which leads to thickness differences in the
applied paste.
[0037] A plating solution may permeate through a portion of an
external electrode where the paste is thinly applied due to a
decrease in density of the portion, such that reliability is
reduced. In addition, glass beading or blisters, where glass is
exposed to a surface, may be generated in a portion where the paste
is thickly applied, should the thickness of the plating layer be
increased to solve a plating defect and a shape defect.
[0038] According to the exemplary embodiment, the external
electrodes may be formed on the outer surfaces of the ceramic body
by a sheet transfer method or a pad transfer method rather than the
existing dipping method, such that the paste for forming an
external electrode may be thinly and uniformly applied.
[0039] Therefore, formation areas of the internal electrodes may be
increased, such that capacitance may be significantly increased as
compared to an existing capacitor having the same size.
[0040] Ceramic sheets on which internal electrode patterns are
formed may be stacked to forma ceramic body 110. The ceramic body
110 includes internal electrodes disposed to face each other with
respective dielectric layers interposed therebetween.
[0041] To form the ceramic body 110, a slurry including powder
particles such as barium titanate (BaTiO.sub.3) powder particles,
or the like, may be first applied and dried onto carrier films to
prepare a plurality of ceramic sheets, thereby forming dielectric
layers.
[0042] The ceramic sheets may be manufactured by mixing ceramic
powder particles, a binder, and a solvent with each other to
prepare a slurry and manufacturing the slurry in a sheet shape
having a thickness of several micrometers by a doctor blade method,
for example.
[0043] Then, a conductive paste including conductive metal powder
particles may be prepared. The conductive metal powder particles
may be powder particles of nickel (Ni) , copper (Cu) , palladium
(Pd), silver (Ag), lead (Pb), or platinum (Pt), or alloys thereof,
may have an average particle size of 0.1 to 0.2 .mu.m. The
conductive paste may be prepared with 40 wt % to 50 wt % of the
conductive metal powder particles.
[0044] The conductive paste for an internal electrode may be
applied to the ceramic sheets by a printing method, or the like, to
form the internal electrode patterns. A method of printing the
conductive paste may be a screen printing method, a gravure
printing method, or the like, but is not limited thereto. Two
hundred or three hundred ceramic sheets on which the internal
electrode patterns are printed may be stacked, pressed, and
sintered to manufacture the ceramic body 110.
[0045] Referring to FIG. 1B, the ceramic body 110 may be pressed
and closely adhered to the sheet 130 for forming an external
electrode to attach the sheet 130 on the ceramic body 110.
[0046] Referring to FIG. 1C, the sheet 130 for forming an external
electrode may be cut by the elastic punching material 160, such
that an external electrode 131 may be formed. External electrodes
may be formed on both end surfaces of the ceramic body 110 in the
length direction of the ceramic body 110, respectively.
[0047] Where the release film 170 is attached to the elastic
punching material 160, the sheet 130 for forming an external
electrode may be cut by the release film 170.
[0048] The sheet 130 for forming an external electrode may be cut
in corner portions of the ceramic body 110 by the release film 170.
Therefore, the external electrodes of the multilayer ceramic
capacitor according to the exemplary embodiment may be formed only
on end surfaces of the ceramic body in the length direction,
respectively, and may be omitted from other surfaces of the ceramic
body.
[0049] That is, the external electrodes 131 may be formed up to
corner portions of the ceramic body 110.
[0050] According to the structure described above, the external
electrodes 131 may be formed on the head surfaces corresponding to
the end surfaces of the ceramic body 110 in the length direction L
of the ceramic body 110, and may or may not be formed formed at a
size as small as possible on all of the band surfaces corresponding
to the four surfaces contacting the head surfaces, such that the
external electrodes may be formed at a thin and uniform
thickness.
[0051] Therefore, formation areas of the internal electrodes may be
increased, such that areas in which the internal electrodes overlap
each other may be significantly increased, whereby a high
capacitance multilayer ceramic capacitor may be implemented.
[0052] The external electrodes 131 may be formed on both end
surfaces of the ceramic body 110 in the length direction of the
ceramic body 110, respectively, by the sheet transfer method or the
pad transfer method as opposed to the dipping method.
[0053] FIG. 1C illustrates a process of forming one external
electrode 131, but a process of forming another external electrode
on the other end surface of the ceramic body 110 in the length
direction of the ceramic body 110 may be added.
[0054] The method of manufacturing a multilayer ceramic electronic
component according to the exemplary embodiment may further include
forming plating layers on the external electrodes. The plating
layers may include nickel plating layers and tin plating layers
formed on the nickel plating layers, but are not necessarily
limited thereto.
[0055] FIGS. 2A through 2C are views illustrating a process of
forming an external electrode of a multilayer ceramic electronic
component according to another exemplary embodiment in the present
disclosure.
[0056] Referring to FIGS. 2A through 2C, a method of manufacturing
a multilayer ceramic electronic component according to another
exemplary embodiment in the present disclosure may further include,
after forming the external electrodes 131 on both end surfaces of
the ceramic body 110 in the length direction of the ceramic body
110, respectively, preparing a member having an elastic pressing
material 140 attached thereto on the surface plate 150 and heating
the surface plate 150 to press and closely adhere the ceramic body
110 to the elastic pressing material 140, thereby extending the
external electrodes 131 to band portions of the ceramic body
110.
[0057] In FIG. 2C, the ceramic body 110 with external electrodes
formed on an end surface may be pressed onto the member having the
elastic pressing material 140 attached thereto and formed on the
surface plate 150 to extend the external electrodes 131 to the band
portions of the ceramic body 110.
[0058] The surface plate 150 may be heated to increase ductility of
the external electrode formed on the end surface of the ceramic
body 110, such that the external electrode may extend to the band
portions of the ceramic body 110.
[0059] In addition, the heated surface plate 150 may increase
adhesion between the ceramic body and the external electrodes.
[0060] The elastic pressing material 140 may be any material having
elasticity, such as a pressing rubber.
[0061] The pressing rubber may have elasticity smaller than that of
the punching rubber, the elastic punching material 160.
[0062] According to the exemplary embodiment, when a thickness of
each of the external electrodes 131 in a central region of the
ceramic body 110 in the thickness direction of the ceramic body 110
is T1 and a thickness of each of the external electrodes 131 at a
point at which the uppermost of the internal electrodes in the
thickness direction is positioned is T2,
0.8.ltoreq.T2/T1.ltoreq.1.2.
[0063] The thickness T1 refers to the length that a virtual line
drawn from a central point of the ceramic body 110 in the thickness
direction and traveling in the length direction overlaps the
external electrode.
[0064] Likewise, the thickness T2 refers to the length that a
virtual line drawn from a position of an uppermost internal
electrode in the thickness direction and traveling in the length
direction overlaps the external electrode.
[0065] The ratio of thicknesses T2 and T1 can satisfy the range
0.8.ltoreq.T2/T1.ltoreq.1.2 to reduce a deviation between the
thickness T1 of each of the electrodes 131 in the central region of
the ceramic body 110 in the thickness direction of the ceramic body
110 and the thickness T2 of each of the external electrodes 131 at
the point at which the uppermost internal electrode is positioned,
whereby deteriorations of reliability may be prevented.
[0066] Where T2/T1 is less than 0.8 or exceeds 1.2, a deviation
between thicknesses of the external electrodes is large, such that
a plating solution may permeate into a thin portion of the external
electrodes, thereby deteriorating reliability.
[0067] According to the exemplary embodiment, when a thickness of
each of the external electrodes 131 in corner portions of the
ceramic body 110 is T3, 0.4.ltoreq.T3/T1.ltoreq.1.0.
[0068] The thickness T3 refers to a thickness of each of the
external electrodes 131 formed on corner regions of the ceramic
body 110.
[0069] The ratio of thicknesses T3 and T1 can satisfy the range
0.4.ltoreq.T3/T1.ltoreq.1.0 to reduce a deviation between the
thickness T1 of each of the electrodes 131 in the central region of
the ceramic body 110 in the thickness direction of the ceramic body
110 and the thickness T3 of each of the external electrodes 131 in
the corner portions of the ceramic body 110, whereby deteriorations
of reliability may be prevented.
[0070] Where T3/T1 is less than 0.4 or exceeds 1.0, a deviation
between thicknesses of the external electrodes is large, such that
a plating solution may permeate into a thin portion of the external
electrodes, thereby deteriorating reliability.
[0071] FIGS. 3A through 3F are views illustrating a process of
forming an external electrode of a multilayer ceramic electronic
component according to another exemplary embodiment in the present
disclosure.
[0072] Referring to FIGS. 3A through 3F, a method of manufacturing
a multilayer ceramic electronic component according to another
exemplary embodiment in the present disclosure may include
attaching an elastic pressing material 140 to a surface plate 150
and preparing a member having a sheet 130 for forming an external
electrode attached thereto on the elastic pressing material 140.
Ceramic sheets on which internal electrode patterns are formed can
be stacked to form a ceramic body 110 that includes internal
electrodes disposed to face each other with respective dielectric
layers interposed therebetween. The ceramic body 110 can be pressed
and closely adhered to the sheet 130 for forming an external
electrode to attach the sheet 130 on the ceramic body 110. The
surface plate 150 can be heated to extend the sheet 130 for forming
an external electrode to band portions of the ceramic body 110. A
member having an elastic punching material 160 attached thereto can
be prepared on the surface plate 150, and ceramic body 110 with
sheet 130 can be pressed and closely adhered onto the elastic
punching material 160 to cut the sheet 130 for forming an external
electrode, thereby forming external electrodes 131 on outer
surfaces of the ceramic body 110.
[0073] Referring to FIG. 3A, the elastic pressing material 140 may
be attached to the surface plate 150, and the member having the
sheet 130 for forming an external electrode attached thereto may be
prepared on the elastic pressing material 140.
[0074] Since the surface plate 150, the elastic pressing material
140, and the sheet 130 for forming an external electrode have been
described above, a description thereof will be omitted, and
contents overlapping those described above are omitted.
[0075] The ceramic sheets on which the internal electrode patterns
are formed may be stacked to form the ceramic body 110 including
internal electrodes disposed to face each other with respective
dielectric layers interposed therebetween.
[0076] Referring to FIG. 3B, the ceramic body 110 may be pressed
and closely adhered to the sheet 130 for forming an external
electrode to attach the sheet 130 on the ceramic body 110.
[0077] In this process, the surface plate 150 may be heated to
extend the sheet 130 to the band portions of the ceramic body
110.
[0078] When the ceramic body 110 is again detached from a member
including the surface plate, the pressing elastic member 140 may be
restored to its original position, and the sheet 130 for forming an
external electrode may be disposed on one end surface of the
ceramic body 110 in the length direction of the ceramic body 110 so
as to extend to the band portions of the ceramic body 110, as
illustrated in FIG. 3C.
[0079] Referring to FIG. 3D, the member having the elastic punching
material 160 attached thereto may be prepared on the surface plate
150. As illustrated in FIG. 3E, the ceramic body 110 with sheet 130
can be pressed and closely adhered onto the elastic punching
material 160 to cut the sheet 130.
[0080] When the ceramic body 110 is again detached from a member
including the surface plate, the punching elastic member 160 may be
restored to its original position, and the sheet 130 for forming an
external electrode may be extended to the band portions of the
ceramic body 110 on one end surface of the ceramic body 110 in the
length direction of the ceramic body 110 to form the external
electrode 131, as illustrated in FIG. 3F.
[0081] A process of forming one external electrode 131 is
illustrated in FIGS. 3A through 3F, but another external electrode
can be formed on the other end surface of the ceramic body 110 in
the length direction of the ceramic body 110.
[0082] The method of manufacturing a multilayer ceramic electronic
component according to the exemplary embodiment may further include
forming plating layers on the external electrodes. The plating
layers can include nickel plating layers and tin plating layers
formed on the nickel plating layers, but are not necessarily
limited thereto.
[0083] Multilayer Ceramic Electronic Component
[0084] A multilayer ceramic electronic component according to an
exemplary embodiment in the present disclosure, particularly a
multilayer ceramic capacitor, will hereinafter be described.
However, the multilayer ceramic electronic component according to
the present disclosure is not limited thereto.
[0085] FIG. 4 is a perspective view of a multilayer ceramic
electronic component according to another exemplary embodiment in
the present disclosure, FIG. 5 is a cross-sectional view taken
along line I-I' of FIG. 4, and FIG. 6 is an enlarged view of region
A of FIG. 5.
[0086] Referring to FIGS. 4 through 6, a multilayer ceramic
electronic component 100 according to an exemplary embodiment in
the present disclosure may include a ceramic body 110, including
internal electrodes 121 and 122, and external electrodes 131 and
132.
[0087] The ceramic body 110 may be in the form of a hexahedron
having both end surfaces in a length direction L, both side
surfaces in a width direction W, and both side surfaces in a
thickness direction T. The ceramic body 110 may be formed by
stacking a plurality of dielectric layers 111 in the thickness
direction T and then sintering the plurality of dielectric layers
111. The shape and dimensions of the ceramic body 110 and the
number of stacked dielectric layers 111 are not limited to those of
the example illustrated in the present exemplary embodiment.
[0088] The plurality of dielectric layers 111 forming the ceramic
body 110 may be in a sintered state, and adjacent dielectric layers
111 may be integrated with each other so that boundaries
therebetween are not readily apparent without using a scanning
electron microscope (SEM).
[0089] The dielectric layer 111 may have a thickness arbitrarily
changed in accordance with a capacitance design of the multilayer
ceramic electronic component 100, and may include ceramic powder
particles having a high dielectric constant, such as barium
titanate (BaTiO.sub.3) based powder particles or strontium titanate
(SrTiO.sub.3) based powder particles. However, a material of the
dielectric layer 111 according to the present disclosure is not
limited thereto. In addition, various ceramic additives, organic
solvents, plasticizers, binders, dispersants, and the like, may be
added into the ceramic powder particles according to an object of
the present disclosure.
[0090] An average particle size of the ceramic powder particles
used to form the dielectric layer 111 is not particularly limited,
but may be controlled in order to accomplish an object of the
present disclosure. For example, the average particle size of the
ceramic powder particles used to form the dielectric layer 111 may
be controlled to be 400 nm or less.
[0091] The internal electrodes 121 and 122 may include a plurality
of first internal electrodes 121 and a plurality of second internal
electrodes 122, provided in pairs and having different polarities,
and may be formed at a predetermined thickness with each of the
plurality of dielectric layers 111 stacked in the thickness
direction T of the ceramic body 110 interposed therebetween.
[0092] The first internal electrodes 121 and the second internal
electrodes 122 maybe formed to be alternately exposed to respective
end surface of the ceramic body 110 in the length direction L of
the ceramic body 110 by printing a conductive paste including a
conductive metal, and may be electrically insulated from each other
by respective dielectric layers 111 disposed therebetween.
[0093] The first and second internal electrodes 121 and 122 may be
electrically connected to the respective first and second external
electrodes 131 and 132 formed on respective end surfaces of the
ceramic body 110 in the length direction L of the ceramic body 110.
The electrical connections may be through the portions alternately
exposed to respective end surfaces of the ceramic body 110 in the
length direction of the ceramic body 110.
[0094] When voltages are applied to the first and second external
electrodes 131 and 132, electric charges may accumulate between
first and second internal electrodes 121 and 122 facing each other.
In this case, capacitance of the multilayer ceramic capacitor 100
may be in proportion to an area of a region in which the first and
second internal electrodes 121 and 122 overlap each other.
[0095] When the area of the region in which the first and second
internal electrodes 121 and 122 overlap each other is significantly
increased, capacitance may be significantly increased even in a
capacitor having the same size.
[0096] According to the exemplary embodiment, since the external
electrodes are thin with uniform thickness, an area in which the
internal electrodes overlap each other may be significantly
increased, such that a high capacitance multilayer ceramic
capacitor may be implemented.
[0097] The widths of the first and second internal electrodes 121
and 122 may be determined depending on an intended use of the
multilayer ceramic capacitor. For example, the widths of the first
and second internal electrodes 121 and 122 may be determined to be
in a range of 0.2 to 1.0 .mu.m in consideration of a size of the
ceramic body 110. However, the widths of the first and second
internal electrodes 121 and 122 according to the present disclosure
are not limited thereto.
[0098] The conductive metal included in the conductive paste for
the first and second internal electrodes 121 and 122 may be nickel
(Ni), copper (Cu), palladium (Pd), silver (Ag), lead (Pb), or
platinum (Pt) or alloys thereof. However, the conductive metal
according to the present disclosure is not limited thereto.
[0099] The external electrodes 131 and 132 may include a first
external electrode 131 and a second external electrode 132
respectively disposed on outer surfaces of the ceramic body
110.
[0100] The external electrodes 131 and 132 may be respectively
disposed only on end surfaces of the ceramic body 110 in the length
direction of the ceramic body 110.
[0101] The external electrodes 131 and 132 may be disposed on
respective end surfaces of the ceramic body 110 in the length
direction up to corresponding corner portions of the ceramic body
110.
[0102] The external electrodes 131 and 132 may include first
electrode layers 131a and 132a and plating layers 131b, 131c, 132b,
and 132c, as illustrated in FIG. 5.
[0103] The first external electrode 131 may include the first
electrode layer 131a disposed on one surface of the ceramic body
110 in the length direction L of the ceramic body 110, and the
plating layers 131b and 131c disposed on the first electrode layer
131a.
[0104] The second external electrode 132 may include the first
electrode layer 132a disposed on the other surface of the ceramic
body 110 in the length direction L of the ceramic body 110, and the
plating layers 132b and 132c disposed on the first electrode layer
132a.
[0105] In the related art, the external electrode is formed by
dipping the ceramic body 110 in a paste that includes a metal
component.
[0106] Where the external electrode is formed by the dipping
method, the paste for the external electrode is not uniformly
applied due to fluidity and viscosity of the paste, which generates
a difference in thickness between a central portion and a corner
portion of the external electrode.
[0107] Where the thickness of the external electrode is not
uniform, glass beading or blister is generated in the central
portion where the applied paste is thick, causing a plating defect
and/or a shape defect, and the corner portion where the applied
paste is thin is vulnerable to permeation of a plating solution,
such that reliability is deteriorated.
[0108] When the paste thickness is increased at the corner portion
to avoid permeation of the plating solution, the paste thickness of
the central portion is increased, which hampers the ability to
increase the size of the ceramic capacitor to increase
capacitance.
[0109] Therefore, in the exemplary embodiment in the present
disclosure, the first electrode layers 131a and 132a may be
disposed on respective end surfaces of the ceramic body 110 in the
length direction L, and the plating layers 131b, 131c, 132b, and
132c may be on the first electrode layers 131a and 132a.
[0110] Since the first electrode layers 131a and 132a are not
formed by the dipping method according to the related art, the
first electrode layers 131a and 132a may be formed on head surfaces
corresponding to the end surfaces of the ceramic body 110 in the
length direction L of the ceramic body 110, and may or may not be
formed formed at sizes as small as possible on all of band surfaces
corresponding to four surfaces contacting the head surfaces.
Therefore, the external electrodes may be formed at thin and
uniform thicknesses.
[0111] Therefore, formation areas of the internal electrodes may be
increased, such that areas in which the internal electrodes overlap
each other may be significantly increased, to implement a high
capacitance multilayer ceramic capacitor.
[0112] According to the exemplary embodiment, the first electrode
layers 131a and 132a may be formed by a sheet transfer method or a
pad transfer method unlike the dipping method according to the
related art.
[0113] Referring to FIGS. 5 and 6, it may be appreciated that the
first electrode layers 131a and 132a are disposed to corner
portions of the ceramic body 110 and are not formed on all of the
band surfaces corresponding to the four surfaces contacting the
head surfaces.
[0114] The first electrode layers 131a and 132a may be formed by
transferring sheets including a conductive metal.
[0115] The first electrode layers 131a and 132a may be formed of
the same conductive metal as that of the first and second internal
electrodes 121 and 122, but are not limited thereto. For example,
the first electrode layers 131a and 132a maybe formed of copper
(Cu), silver (Ag), nickel (Ni), or alloys thereof.
[0116] The plating layers 131b, 131c, 132b, and 132c may be
disposed on the first electrode layers 131a and 132a.
[0117] That is, the plating layers 131b, 131c, 132b, and 132c may
be disposed on the head surfaces corresponding to the end surfaces
of the ceramic body 110 in the length direction L of the ceramic
body 110.
[0118] Particularly, the plating layers 131b, 131c, 132b, and 132c
may be formed on the head surfaces corresponding to the end
surfaces of the ceramic body 110 in the length direction L of the
ceramic body 110, and may be omitted from both side surfaces of the
ceramic body 110 in the width direction of the ceramic body 110 and
the upper and lower surfaces of the ceramic body 110.
[0119] The plating layers 131b, 131c, 132b, and 132c may include
nickel plating layers 131b and 132b and tin plating layers 131c and
132c each disposed on the nickel plating layers 131b and 132b, but
are limited thereto.
[0120] According to the exemplary embodiment, the ratio of the
thicknesses T2 and T1 satisfies the range
0.8.ltoreq.T2/T1.ltoreq.1.2 to reduce a deviation between the
thicknesses T1 and T2 and thereby prevent deteriorations of
reliability.
[0121] Where T2/T1 is less than 0.8 or exceeds 1.2, a deviation
between thicknesses of the external electrodes is large, such that
a plating solution may permeate into a thin portion of the external
electrodes, thereby deteriorating reliability.
[0122] Contents overlapping those described above in relation to
the method of manufacturing a multilayer ceramic electronic
component have been omitted from this description of an exemplary
embodiment of the multilayer ceramic electronic component.
[0123] As set forth above, in the multilayer ceramic electronic
component according to the exemplary embodiment in the present
disclosure, the external electrodes may have a thin and uniform
thickness, and thus, formation areas of the internal electrodes may
be increased, such that areas in which the internal electrodes
overlap each other may be significantly increased, whereby a high
capacitance multilayer ceramic capacitor may be implemented.
[0124] In addition, a deviation between thicknesses depending on
positions of the external electrodes may be reduced, whereby a
subminiature high capacitance multilayer ceramic capacitor having
excellent reliability may be implemented.
[0125] While exemplary embodiments have been shown and described
above, it will be apparent to those skilled in the art that
modifications and variations could be made without departing from
the scope of the present invention as defined by the appended
claims.
* * * * *